Evening sky on Sunday, October 13 as seen from Adelaide at 20:09 ACDST (45 minutes after sunset), C/2023 A3 Tsuchinshan-ATLAS may be visible in the twilight, in the coming days it will rise higher in the twilight should become visible to the unaided eye possibly with a nice little tail. Similar views will be seen from the rest of Australia at roughly the equivalent local time (45 minutes after sunset, click to embiggen). |
Evening sky on Tuesday, October 15 as seen from Adelaide at 20:11 ACDST (45 minutes after sunset), C/2023 A3 Tsuchinshan-ATLAS may be visible in the twilight. Similar views will be seen from the rest of Australia at roughly the equivalent local time (45 minutes after sunset, click to embiggen). |
Evening sky on Saturday, October 19 as seen from Adelaide at 20:31 ACDST (60 minutes after sunset), C/2023 A3 Tsuchinshan-ATLAS should be visible in the twilight. Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes after sunset, click to embiggen). |
Evening sky on Saturday, October 26 as seen from Adelaide at 20:31 ACDST (60 minutes after sunset), C/2023 A3 Tsuchinshan-ATLAS should be visible in the twilight, although you may need binoculars. Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes after sunset, click to embiggen). |
Path of C/2023 A3 Tsuchinshan-ATLAS in the western evening sky from 9 October on. Black&White chart suitable for printing (click on the image to embiggen and print). The image is at civil twilight 30 minutes after sunset to show the path of the comet over the month, however, the best time to observe is nautical twilight (60 minutes before sunrise). The circle is the approximate field of view of 10×50 binoculars. The greyed out section is below the horizon. The path of Venus and Mercury is also shown. |
Binocular hart of the path of C/2023 A3 Tsuchinshan-ATLAS in the western evening sky from 13 October on.
Black&White chart suitable for printing (click on the image to |
Brightness chart of comet C/2023 A3 Tsuchinshan-ATLAS from Gideon van Buitenen’s website.
The long anticipated comet C/2023 A3 Tsuchinshan-ATLAS has been putting on a nice show for early risers (although the spectacular images are all zoomed in long exposures, most people see fuzzy dots with their unaided eyes).
The comet is now too deep in the twilight to be seen. It will return to western evening twilight from around 12 October. It has been preforming better than expected, and while the most optimistic predictions of it’s potential brightness are unlikely to be fulfilled, it looks like it will peak somewhere around magnitude -3 to -4, around as bright as Venus, it will be around 8° from the Sun, and unlikely to be seen at its brightest. How bright it will be when it emerges from the twilight is still uncertain.
Probably the earliest most of us will be able to see the comet is next Saturday, 12 October, when it is closest to the Earth. You will need a level, unobstructed horizon to see it, as it is only a degree above the horizon, and binoculars. Although theoretically visible to the unaided eye, the atmospheric density near the horizon and the bright twilight will mean the comet will be obscured. Through binoculars it may be a fuzzy dot, depending on exactly how its brightness evolves.
The printable black and white charts above will help you locate the comet, you may need binoculars first to locate it before you can spot is with your unaided eye. Fortunately Venus is a bright landmark, and if you sweep down from Venus with binoculars you should be able to catch the comet.
Although the comet may be obscured, it is possible to catch the tail above the horizon as twilight deepens.
C/2023 A3 Tsuchinshan-ATLAS rapidly climbs into darker skies, unfortunately dimming as it goes, but long exposure images should catch it quite nicely even if it looks like a fuzzy dot to the unaided eye.
The comet should remain visible for the rest of October (although possibly only in binoculars towards the end), at the same time you will be able to follow Venus moving through the Scorpion and Mercury rising towards the head of the Scorpion too.
Labels: binocular, C/2023 A3, comet, unaided eye